Derailment of train 7SP3
Roto, New South Wales, 4 March 2012
ATSB Transport Safety Report
Rail Occurrence Investigation
RO-2012-002
Final – 30 August 2013
Cover photo:
Source ATSB
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Addendum
Page
Change
Date
Safety summary
What happened
Floodwater adjacent to track
On the morning of 4 March 2012, freight train 7SP3 operated
by Pacific National derailed after entering floodwaters that had
overtopped the track near Roto in New South Wales.
The flooding had caused scouring of the track formation,
compromising its capacity to support the train.
The lead locomotive remained on the track but the trailing
locomotive derailed and uncoupled. None of the trailing
wagons derailed although a number sustained damage. The
flooding and subsequent derailment of the second locomotive
of train 7SP3 damaged approximately 130 m of track. The
crew were shaken, but physically unhurt.
Source: Local resident
What the ATSB found
The ATSB determined that runoff from the heavy rain that had fallen in the catchment area
adjacent to Roto the morning of 4 March 2012 caused a flash flood event. The volume of
floodwater exceeded the capacity of a drainage culvert, which resulted in water overtopping the
track formation with ballast and sub-grade scouring on either side of the culvert.
The magnitude of the scouring meant that the track could not support the weight of train 7SP3 as
it passed over the affected areas. The resulting deformation in the alignment of the track initiated
the derailment.
The ATSB also found that the track manager’s systems and operational procedures provided
limited information and guidance to assist the network control staff in identifying and assessing the
potential threat to the safety of rail traffic resulting from the significant localised weather event.
What's been done as a result
The track manager is trialling the use of flood sensors at high-risk locations and has engaged the
services of a third party to provide early warning information on potential high-risk weather events.
Safety message
It is essential that rail transport operators have robust systems in place to monitor and mitigate the
risks to infrastructure from significant weather events to ensure that the safety of rail operations is
not compromised.
Contents
The occurrence ........................................................................................................................1
Events prior to derailment
1
The derailment
3
Events post derailment
4
Context ......................................................................................................................................7
The location
7
Train and train crew information
7
Environmental conditions
7
Track information
9
Track drainage - design
9
Track drainage - inspections
10
Other weather related occurrences
11
Safety analysis ...................................................................................................................... 12
Introduction
12
Development of the occurrence
12
Safety management system
12
Findings ................................................................................................................................. 14
Contributing safety factors
14
Other safety factors
14
Other key findings
14
Safety issues and actions ................................................................................................... 15
Response to significant weather events
15
Safety issue description:
15
General details ...................................................................................................................... 17
Occurrence details
17
Train details
17
Sources and submissions .................................................................................................. 18
Sources of information
18
References
18
Submissions
18
Appendices ........................................................................................................................... 19
Appendix A – Weather event and rainfall
19
Australian Transport Safety Bureau .................................................................................. 22
Purpose of safety investigations
22
Developing safety action
22
ATSB – RO-2012-002
The occurrence
Events prior to derailment
In the days prior to the derailment of Pacific National (PN) train 7SP3, a slow moving low-pressure
trough generated a broad rainband across New South Wales. The Bureau of Meteorology (BoM)
had forecast severe weather and issued flood warnings for various areas of the State.
At 0543 on 3 March 2012, the BoM predicted rain for the Riverina District (including Roto at the
northern extremity), becoming heavy at times in the north, with the chance of thunderstorms in the
northwest. A severe weather warning with flash flooding1 of a number of rivers and river valleys
within the district was current. The rainfall from this weather system caused substantial runoff
resulting in the saturation of catchment areas and the pooling of floodwater adjacent to the rail
track at a number of locations between Broken Hill and Parkes.
At about 0545 on 3 March 2012, the crew of freight train 4PS6 travelling from Broken Hill towards
Parkes reported to the Australian Rail Track Corporation (ARTC) Network Control Officer (NCO)
that floodwater had overtopped the ballast at two locations between Yarrabandai and Bogan Gate.
The NCO relayed this advice to the ARTC track maintenance contractor, Transfield Services
Australia (Transfield) to follow-up. Track supervisors from Transfield began a series of
unscheduled inspections2 of the track, travelling west from Goobang Junction and east from
Condobolin. Track supervisors from Menindee and Broken Hill also began to conduct track
inspections (Figure 1).
Figure 1: Location of Roto, New South Wales
Source: Geoscience Australia Crown Copyright ©
Shortly after 0745, the Condobolin supervisor inspecting the line toward Bogan Gate reported to
the NCO that rain continued to fall and floodwater had overtopped the track between Yarrabandai
1
2
Flash flooding is defined as 'flooding occurring within about 6 hours of rain, usually the result of intense local rain and
characterised by rapid rises in water levels' (Bureau of Meteorology, Weather Services Handbook).
Unscheduled waterway and drainage inspection carried out in response to reported flooding or heavy rain in areas
prone to flooding (e.g. by drivers) to allow required actions to be determined. Source: ARTC Engineering (Track and
Civil) Code of Practice Section 10 Flooding
›1‹
ATSB – RO-2012-002
and Bogan Gate. The supervisor advised his intention to wait for the supervisor travelling from
Goobang Junction to arrive before making a final assessment of the conditions. At about this time
the ARTC Train Transit Manager (TTM) joined the conversation to confirm an inspection of the
track between Ivanhoe and Broken Hill should occur, as he had observed BoM radar images
indicated rainfall around that area. The Condobolin supervisor then departed travelling west
toward Ivanhoe, later advising the NCO that he had received reports of rainfall measurements of
25 mm and 75 mm from residents in the Roto and Ivanhoe areas respectively.
At about 1035, the Goobang Junction supervisor arrived at the flood-affected area between
Yarrabandai and Bogan Gate. He advised the NCO to hold trains at Goobang Junction until
midday due to rising floodwaters. Supervisors from Condobolin, Menindee and Broken Hill
continued the track inspections, identifying that although rain was continuing to fall and that there
was widespread pooling of rainwater runoff adjacent to the track, the under-track drainage
systems appeared to be coping with the volume of water. The track supervisor from Broken Hill
took the precaution of issuing a Condition Affecting the Network (CAN)3 warning for floodwaters
near Menindee.
At about 1120, the Goobang Junction supervisor advised that floodwater had receded sufficiently
to allow the passage of trains under a CAN warning that restricted track speed to 40 km/h through
the affected area. Train 6SP6 departed Goobang Junction at about 1330, followed later that
afternoon by train 6NY3 at about 1450. The NCO provided advice of the CAN warnings in the
relevant Train Order4 issued to the crew of each train.
Following the passage of trains 6SP6 and 6NY3 through the flood-affected area between
Yarrabandai and Bogan Gate, a scheduled BoM forecast (issued at about 1632) identified
continuing rain, heavy at times with similar conditions expected the following day before easing.
The severe weather warning for flash flooding within the Riverina District remained current.
The Goobang Junction supervisor, after continuing with track inspections, later assessed that the
level of floodwater had receded sufficiently to cancel the CAN warning and update the speed
restriction to 70 km/h. As trains 6SP6 and 6NY3 travelled toward Broken Hill, the Condobolin,
Menindee and Broken Hill track supervisors continued to inspect the track ahead of the trains.
At about 1710, the Condobolin track supervisor had returned to Roto, reporting to the NCO that
his vehicle was clear of the track and that train 6NY3 could pass. The supervisor advised that
although it was still raining, the drainage pipes under the track formation were handling the flow of
water satisfactorily and that it was his expectation that this situation should continue, so long as
there was not a downpour within the next 8 hours.
The supervisor requested that if there was further rain, the NCO warn train crews to keep watch
for signs of flooding from Condobolin onward.
The Condobolin supervisor departed Roto at about 1845 and headed towards Condobolin,
clearing the track at Euabalong West at about 2108 for the passage of the next train, 7GP1. When
the supervisor booked clear of the track, he advised the NCO that although there was water
pooling, the condition of the track was good. The supervisor then returned to Condobolin, finishing
work at around 2200. Following the inspection, two train movements passed through the Roto
area, 7GP1 at around 2237 that evening followed by 6SP7 at about 0050 on the morning of the
derailment.
The crews of the two preceding trains communicated no concern to the NCO related to the
potential for flooding of the track between Goobang Junction and Broken Hill. Following
3
4
A situation or condition that affects or has the potential to affect the safety of the ARTC Network Source: ARTC
Glossary, Issue 2.0 – Rev. 0, 19 Dec 2010
An instruction, on the prescribed form, issued by the train controller, in train order territory to direct the movement of rail
traffic Source: RISSB National Guideline Glossary of Rail Terminology 3 December 2010
›2‹
ATSB – RO-2012-002
discussions between the NCO and crew of train 7GP1, the NCO decided to cancel the remaining
CAN warning for the Menindee area at about 0400 on 4 March 2012.
The derailment
At about 0315 on 4 March 2012, the driver and co-driver involved in the derailment commenced
their shift at Goobang Junction. Due to a delay with their originally scheduled train service, they
were re-rostered to work train 7SP3 to Broken Hill, departing Goobang Junction at about 0400.
Shortly after reporting the train’s departure to the NCO, the driver asked where the flooding was
on the track ahead. The NCO advised that most of the reports were on the previous day in the
area between Euabalong West and Matakana and restrictions were in place from Yarrabandai to
Bogan Gate (Figure 1). The NCO also advised that the drivers of the previous trains (7GP1 and
6SP7) had not reported anything unusual.
The driver of train 7SP3 had worked a train through Bogan Gate the previous day. He was
concerned about the track condition he had experienced the previous day and as a precaution
decided to maintain the train at a reduced speed of 40 km/h between Bogan Gate and the next
passing loop at Yarrabandai. After passing through Yarrabandai, the driver accelerated the train to
the posted track speed.
Train 7SP3 continued without incident to Condobolin where the co-driver, who was undergoing
training, took over to drive the train onward under the supervision of the mentor driver (now the codriver).
As train 7SP3 approached Roto light rain had begun to fall; the intensity increased as the train
passed through Roto. At about 0711, train 7SP3 traversed the level crossing located to the west of
Roto (Figure 2). The train was travelling at approximately 93 km/h when the mentor driver
observed ‘white water’ flowing over the track ahead and instructed the trainee driver to apply the
train brake. The trainee driver made a normal operating mode brake application of around 70-kpa.
Figure 2: Derailment site west of Roto
Source: Google ©
Shortly after the brake application the mentor driver intervened: he moved over to the controls and
applied full dynamic braking. He followed this with a full application of the independent brake and
service brake (Figure 3). At that point, the mentor driver resumed his seat and instructed the
trainee driver to brace, should the train not stop before entering the water.
›3‹
ATSB – RO-2012-002
Figure 3: Data logger composite plot for locomotives NR116 and NR27 of train 7SP3
The train was unable to stop and as the lead locomotive (NR116) traversed the floodwater, the
crew reported that the locomotive hit two distinct dips in the track that were about 25 m apart. The
drivers felt a significant impact as the locomotive exited each dip, with the second being more
severe and resulting in water covering the locomotive windscreen. As the train progressed through
the water the lead locomotive remained on track, but the trailing locomotive, (NR27) uncoupled
and collided with the rear of the lead locomotive.
The lead locomotive came to rest about 300 m past the second washaway site. After an initial
assessment of the situation, the mentor driver contacted the NCO. He advised that they had
passed through Roto and that train 7SP3 had encountered a washaway and had derailed.
Events post derailment
Due to the extent of floodwater and the unstable nature of the ground, the crew were only able to
inspect the leading 100 m of the train (the train was 1508 m long). During the inspection, they
became concerned about the rising water level and the risk of continued undermining of the
formation, which they felt would further compromise to the stability of the track (Figure 4).
On returning to the lead locomotive, the crew carried out temporary repairs to the brake pipe taps
damaged by the collision between the two locomotives and updated the NCO on the status of the
train and track. The crew observed that the floodwaters were rising along the track and sought
permission from the NCO to move NR116 to higher ground.
›4‹
ATSB – RO-2012-002
Figure 4: Floodwaters adjacent Roto culvert, viewed in easterly direction toward Roto
Source: Local resident
At about 0844, the NCO gave permission and the train crew moved locomotive NR116 forward
approximately 1,000 m. The crew observed that the water level near the derailment site continued
to rise.
At around 1016, the NCO issued a Train Order for locomotive NR116 to travel to the next location.
The crew departed, arriving at Trida at about 1122, where they stabled the locomotive in the
goods siding.
The crew remained at Trida until about 1536 when a Transfield road-rail vehicle5 arrived from
Broken Hill to transport the crew to Broken Hill.
Later in the day, a light locomotive6 dispatched from Goobang Junction arrived at Roto to recover
the rear portion of train 7SP3. At about 2200, PN removed the rear portion of 7SP3 from the
derailment site and returned it to Goobang Junction. The derailed locomotive NR27 and seven
wagons (four of which were multiple platform wagons) that had sustained damage remained at the
derailment site for later recovery.
After floodwaters receded, repairs to the locomotives and remaining wagons of train 7SP3 were
completed. At about 0750 on Thursday 8 March 2012, PN completed the removal of all rail
vehicles from the derailment site. Transfield maintenance personnel undertook repairs to the
washed out formation and damaged concrete sleepers (Figure 5). At about 1230 on Friday 9
March 2012, Transfield staff completed repairs and reopened the track.
5
6
A road vehicle fitted with retractable rail guidance wheels. Source : RISSB National Guideline Glossary of Rail
Terminology 3 December 2010
A locomotive or locomotives coupled without vehicles. Source: RISSB National Guideline Glossary of Rail Terminology
3 December 2010
›5‹
ATSB – RO-2012-002
Figure 5: Wash-away damage to track formation adjacent Roto culvert, viewed toward
Roto (note the same perspective to Figure 4)
Source: ATSB
›6‹
ATSB – RO-2012-002
Context
The location
The derailment occurred about 2.2 km west of Roto at the 709.187 km mark7 on the Defined
Interstate Rail Network (DIRN) in New South Wales (Figure 6). Roto is located approximately
262 km west of Parkes and 418 km east of Broken Hill by rail.
Figure 6: Location of Roto, New South Wales
Source: Geoscience Australia Crown Copyright ©
Train and train crew information
Train 7SP3 was a freight service operated by Pacific National (PN) between Sydney and Perth. It
consisted of two locomotives (NR116 leading and NR27 trailing) hauling 45 freight wagons of
which 10 were multiple platform type. The train was 1508 m in total length and had a trailing mass
of 3524.1 t.
The crew consisted of a driver and co-driver. At the time of derailment, the driver was a ‘driver-intraining’ with around six months experience in the rail industry. He was operating the train under
the supervision of the co-driver (mentor driver) who had 36 years of experience in the rail industry.
The driver-in-training and mentor driver held appropriate competencies for the tasks being
performed and had been assessed as fit for duty in accordance with the requirements of the
National Standard for Health Assessment of Rail Safety Workers.
The crew of train 7SP3 on sighting fast flowing floodwaters overtopping the track formation ahead
reacted reasonably in braking the train. There was no anomaly identified in the train speed,
handling, rollingstock condition, or operational performance leading up to the derailment.
The consignment of train 7SP3 included dangerous goods. There was no loss of containment of
these goods due to the derailment.
Environmental conditions
The closest BoM weather station to the derailment site was at Hillston (Mount View), about 20 km
southwest of Roto. On the day of the occurrence Hillston weather station recorded a daily rainfall
total of 114 mm. Significant rainfall had also been recorded in the areas around Ivanhoe and
Hillston Airport which are located to the west and south of Roto respectively. This rainfall occurred
7
Distance in track kilometres from a reference point located at Sydney Central Station.
›7‹
ATSB – RO-2012-002
in conjunction with a broad rainband arising from a low-pressure trough that extended across
NSW (Appendix A – Weather event and rainfall).
A severe weather warning for flash flooding issued by the BoM was current for the Riverina
District forecast area of New South Wales, which included Roto. Post-accident analysis (Appendix
A – Weather event and rainfall) suggests that the intensity of rainfall at Hillston, averaged over a
24-hour period, was equivalent to a 50-year precipitation event. A resident in the Roto area noted
that the rainfall was particularly heavy on the morning of 4 March 2012 and recorded about 70 mm
in a 3 to 4 hour period (a fall that would exceed a 100-year precipitation event). Based on the
available information, the intensity of the rainfall in the Roto area that fell on an already saturated
catchment was almost certainly well in excess of a 50-year rainfall intensity event and was the
cause of flash flooding in the area.
Rainwater runoff resulted in the pooling of water against the track formation at a number of
locations between Parkes and Broken Hill. The extent of flooding that occurred near the
derailment site at Roto area was evident by the water debris mark on the track formation
extending both east and west of the wash-away site (Figure 7).
The crew reported that light rain was still falling as train 7SP3 approached Roto at about 0710.
Sunrise was at 0708 with morning civil twilight8 occurring at 0643.
Figure 7: Flooding water mark on northern face of formation, viewed from the east of the
wash-away site.
Source: ATSB
8
Defined as the instant in the morning, when the centre of the Sun is at a depression angle of six degrees below an ideal
horizon. At this time in the absence of moonlight, artificial lighting or adverse atmospheric conditions, the illumination is
such that large objects may be seen but no detail is discernible. Source: Geoscience Australia
›8‹
ATSB – RO-2012-002
Track information
The Australian Rail Track Corporation (ARTC) manages the railway where the derailment
occurred, with the movement of rail traffic controlled from the ARTC’s Network Control Centre
located at Mile End in South Australia. Transfield Services Australia were contracted by the ARTC
to provide maintenance and inspection services for the railway infrastructure in the area of the
derailment.
The standard gauge (1435 mm) track at the derailment location consisted of 53 kg/m rail fastened
to concrete sleepers by resilient clips. The track formation comprised sand/clay based soil topped
with a capping layer and overlaid with ballast to a nominal design ballast depth of 250 mm forming
the track bed.
The track bed supported prestressed concrete sleepers spaced at about 667 mm centres. The
ARTC undertook the installation of concrete sleepers between Parkes and Broken Hill under its,
East/West Productivity Resleepering works project which was completed in February 2012.
Approaching the derailment site from Roto, the track was tangent9 and the terrain undulating. The
track gradient adjacent the derailment site transitioned from a falling grade of 1:597, through level,
to a rising grade10 of 1:301.
Track drainage - design
The design and construction of the track between Parkes and Broken Hill occurred prior to the
ARTC leasing the interstate main line from the NSW Government on 4 September 2004. The
ARTC does not have any records relating to hydrology calculations used to design the under-track
drainage systems for the track section through the Roto area or of any subsequent assessment of
the drainage capacity, other than routine maintenance inspections. Since taking up the lease, the
ARTC has progressively transitioned infrastructure standards adopted from the previous operator
into an Engineering (Track & Civil) Code of Practice (CoP). The CoP requires new waterway
structures be designed in accordance with Australian Rainfall and Runoff11 and Australian
Standard AS5100.
The drainage system in the Roto area included a series of small under-track culverts installed at
intervals along the track to drain the rainwater runoff from the catchment situated to the north of
the railway. The culverts each consisted of a group of four 600 mm diameter corrugated metal
pipes. The small under-track culvert located at the 709.187 km mark, adjacent to the derailment
site, was the only culvert to sustain significant damage because of the runoff of rainwater on the
morning of 4 March 2012 (Figure 8).
The CoP specifies the minimum flood opening for minor under track structures, such as the
culverts at Roto, should accommodate the discharge for a 50-year return precipitation event. In
this case, the intensity of rainfall in the Roto area almost certainly exceeded the minimum design
criteria documented in the CoP and potentially exceeded the 100-year return precipitation event,
significantly increasing the risk of flash flooding that would top the track and compromise the track
structure. Consequently, the investigation focused on the management of rail safety under
significant weather conditions that had the potential to exceed the designed drainage capacity of
the track structure.
9
10
11
Straight track with no applied cant. Source: RISSB National Guideline Glossary of Rail Terminology 3 December 2010.
A measure of the rate at which the railway is inclined (rising or falling) Gradients are signed +ve (rising) or –ve (falling)
in respect of the direction of travel. Source: RISSB National Guideline Glossary of Rail Terminology 3 December 2010.
Australian Rainfall and Runoff (ARR) is a national guideline document for the estimation of design flood characteristics
in Australia.
›9‹
ATSB – RO-2012-002
Figure 8: Roto Culvert, northern side view 12
Source: Australian Rail Track Corporation Copyright ©
Track drainage - inspections
The CoP specifies the inspection and assessment arrangements applicable to drainage systems
installed throughout the ARTC network. Inspections of waterways and drainage systems are
categorised as scheduled or unscheduled; the latter may be in response to conditions arising from
a weather event.
Areas identified as prone to flooding may additionally be declared ‘special locations’. Special
locations are subject to unscheduled inspections in response to defined rain events or an alarm
from automatic monitoring systems that may be installed at those locations. Such inspections are
undertaken to collect information on the physical condition of the waterway in flood and to monitor
conditions until the risk to train operations is assessed as acceptable13. For areas that are not
identified as special locations, unscheduled inspections may be triggered in response to automatic
rainfall monitoring, reports of flooding by train drivers or heavy rains in areas prone to flooding.
In the time preceding the derailment of train 7SP3, unscheduled inspections were conducted to
assess the condition of waterways and drains at various locations between Goobang Junction and
Broken Hill. The inspection at Roto was undertaken at about 1845 on Saturday 3 March 2012 and
had assessed the conditions as suitable for rail traffic, provided there was not a downpour in the
next 8 hours. Two trains passed through Roto (the last at about 0050 on Sunday 4 March 2012)
without reporting any increased flooding hazard. By the time train 7SP3 arrived at Roto (about 6
hours later), the conditions had unknowingly changed and floodwaters had topped the track
resulting in a compromised track structure.
12
13
Picture in Figure 8 was taken prior to installation of concrete sleepers during East/West Productivity Resleepering
works.
ARTC Engineering (Track & Civil) Code of Practice, Section 10 Flooding, Version 2.2, 08 November 2011
› 10 ‹
ATSB – RO-2012-002
Other weather related occurrences
The ATSB has investigated two similar flood related weather occurrences. The first occurred near
Golden Ridge14 in Western Australia on 30 January 2009 involving the ARTC and the second at
Edith River15 in the Northern Territory on 27 December 2011 involving Genesee and Wyoming
Australia (GWA).
The Golden Ridge investigation identified safety issues concerning the specification of
hydrological design parameters in the CoP, the audit and assessment of the track drainage
arrangements, and the timely access to reliable weather information identifying localised severe
weather events that may affect the safety of the track. Although the ARTC had not identified any
corrective action as a specific response to each of these safety issues, a track wash-away risk
assessment was undertaken in late July 2009. The risk was assessed in relation to a hypothetical
track wash-away occurring either to the east or to the west of Coonamia in South Australia16. The
ARTC identified mitigation plans which included hydrology assessments and trialling the sourcing
of specialist meteorologist services to provide advanced warning of weather events.
The ARTC initiated a limited trial of the meteorological advanced warning services for certain
weather events in November 2012 with the full implementation of the service occurring in March
2013. The review of the hydrology design was completed for the track west of Broken Hill and
through South Australia in June 2013. The mitigation plans were initiated and implemented after
the derailment of 7SP3 at Roto, but generally focused on the track west of Broken Hill. The
opportunity exists for the ARTC to carry out a similar review to the east of Broken Hill, particularly
given that the ARTC does not have access to the hydrology calculations used to design the undertrack drainage systems for the track section through the Roto area.
The Edith River investigation identified safety issues related to limitations in the policies,
procedures and training provided to employees in managing severe weather events and
ineffective warning systems in place to alert staff to the severity of a flood event. GWA, in
response, initiated a review of their Extreme Weather Event Monitoring and Response Procedure
and their Cyclone Response Plan to incorporate learning’s from the occurrence. Awareness
training packages were developed to provide operational staff, track inspectors and management
guidance on the recommended responses to flooded track, storms and extreme wind events. In
conjunction with the above, GWA instigated systems to detect stream flow and alert train control
and train crews. Arrangements were also formalised with a number of agencies, including the
BoM for the reporting and monitoring of extreme weather events.
14
15
16
ATSB investigation number, RO-2009-003 - Derailment of Train 5PS6 near Golden Ridge WA 30 Jan 2009
ATSB investigation number, RO-2011-019 - Derailment of freight train 7AD1 at Edith River near Katherine NT on
27 December 2011
The ARTC considered that the potential consequence of a wash-away to the west of Coonamia was different to the
consequence of a wash-away to the east.
› 11 ‹
ATSB – RO-2012-002
Safety analysis
Introduction
Railway infrastructure is designed, constructed and maintained in accordance with applicable
engineering standards to ensure serviceability in wide range of foreseeable weather conditions.
Significant weather events, which produce conditions which exceed defined design parameters,
increase the likelihood of degradation of the infrastructure and thereby increase the risk to the
safety of rail operations.
The ability of a rail infrastructure manager to assess the risks arising from significant weather
events and implement appropriate precautionary measures is therefore essential in providing a
safe system for rail operations.
Development of the occurrence
On the day preceding the derailment, the ARTC initiated unscheduled inspections between
Parkes and Broken Hill following reports of heavy rainfall and flooding. The track supervisor
inspecting the Roto area advised the NCO that the drainage pipes were coping with the flow
provided there was not another downpour in the next 8 hours. This qualification suggests that the
track supervisor assessed conditions were likely to deteriorate if further heavy rain fell.
After the unscheduled inspections ended, the NCO continued to monitor the condition of the track
through feedback from the train crews as they reported on progress through track sections. This
feedback and the uneventful passage of train services 7GP1 and 6SP7 that passed through Roto
6 hours before the train that derailed probably created a belief that the weather system had
abated and the risk of further track flooding had passed.
The weather forecast issued by the BoM, however, continued to warn of heavy rainfall and the
potential for flash flooding in the district. This information, supported by radar images available
from the BoM website and reports from track supervisors and train crews of widespread pooling of
water in the saturated catchments adjacent the track, signalled the presence of an ongoing hazard
to the railway from this weather event.
Between the passage of train 6SP7 through Roto at 0050 and the derailment of train 7SP3 at
0711, localised heavy rainfall caused significant rainwater runoff from the adjacent catchment.
Information available from the BoM and local residents substantiate that the intensity of the rainfall
was almost certainly in excess of a 50-year rainfall intensity event.
This resulted in property damage and scouring to an adjoining property that had not occurred with
the previous falls that week (Appendix A – Weather event and rainfall) and a flash flood that
overtopped the rail track adjacent to the culvert at the 709.187 km mark, causing significant
scouring of the formation. The damage to the formation compromised its integrity to the extent that
the track could not support the weight of a train.
Neither the NCO nor the train crew were aware of the extreme rainfall event and changed
conditions that created the localised threat. This was the critical factor in the occurrence.
Safety management system
At the time of the derailment, the ARTC managed risk to safety through the implementation of its
Safety Management System (SMS). A key component of the SMS is the development of
procedures to address the various general engineering and operational systems safety
requirements. In this case, the CoP addresses the engineering design parameters for waterways
and drains as well as specifying the requirement for scheduled and unscheduled inspections of
those waterways.
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ATSB – RO-2012-002
The CoP states that reports of heavy rain or flooding from train crews, or other sources, may
trigger unscheduled inspections to assess the condition of the waterways and drains. Track
supervisors determine what action is required based on their assessment of the prevailing
conditions at that location.
The unscheduled inspection, while essential to identify infrastructure defects or the development
of other issues observable at that time, is limited to the extent that it cannot assess risk to train
operations from changed weather conditions following the inspection and prior to the passage of
the next train.
After the unscheduled inspections ended, the NCO relied on the crews of trains passing through
the affected area to assess the condition of infrastructure and provide feedback. In this case, there
was a 6-hour period without any visual feedback of track condition, during which weather
conditions resulted in flash flooding around the Roto area.
The applicable Safeworking Rules and Procedures govern the operational requirements for the
movement of trains on the ARTC NSW network. These rules and procedures prescribe the
actions that the NCO undertakes in response to a report from train crew or maintenance
personnel of unsafe conditions. In this occurrence, the NCO issued CAN warnings in response to
the advice from track supervisors undertaking the unscheduled inspections. Once the
unscheduled inspections had ceased and the CAN warnings had been cancelled, the rules and
procedures provided no additional guidance or instruction to the NCO in assessing and managing
the continuing risk from this weather event.
There are, however, operational rules and procedures that provide guidance and instruction to the
NCO about the actions or speed restrictions required to manage the movement of trains during
events such as very hot weather or the triggering of an automatic rainfall monitoring warning at a
special location. The ARTC operational rules and procedures provided few if any additional
sources of information or guidance to the NCO or other network control staff to quantify the
response and duration for managing risk during this significant weather event.
The ATSB investigation into the derailments at Golden Ridge and Edith River identified similar
inadequacies in each operator’s safety management systems (the ARTC and GWA). Although the
ARTC has undertaken risk assessments and implemented mitigation plans, including the
provision of specialist meteorological warning services, the provision of instruction to the NCOs
with respect to dealing with a significant weather events was not identified. The ARTC advised
that they consider the management of weather events, subject to the specific circumstances of
each event, as equivalent to managing any other condition that may affect the rail network.
However, as is evident from the derailment at Roto, the absence of sufficient information,
guidance, operational procedures or training to aid network control centre staff in assessing
consequential hazards from a weather event, prior to dispatching trains, increases risk to
operations on the railway.
Significant weather events do pose a significant operational risk and, although infrequent, the
consequences of a derailment resulting from a wash away can involve injury and significant
property damage. Significant weather events are a recognised hazard and risk management
standards require the development and application of all reasonable and practicable measures to
mitigate the effects of the associated risk. It is therefore a requirement that operators understand
the nature of significant weather events, as they relate to their operations, and develop strategies
that provide for the safety of the rail services operating on their network.
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ATSB – RO-2012-002
Findings
At approximately 0715 on 4 March 2012, freight train 7SP3 travelling from Sydney to Perth
derailed after entering a washed out area of track formation where floodwaters were overtopping
the rails near Roto, in New South Wales (NSW). The floodwaters developed from a high intensity
rainfall event that occurred in conjunction with a period of sustained wet weather experienced in
the area.
From the evidence available, the following findings are made with respect to the derailment but
should not be read as apportioning blame or liability to any particular organisation or individual.
Safety issues, or system problems, are highlighted in bold to emphasise their importance.
A safety issue is an event or condition that increases safety risk and (a) can reasonably be
regarded as having the potential to adversely affect the safety of future operations, and (b) is a
characteristic of an organisation or a system, rather than a characteristic of a specific individual, or
characteristic of an operating environment at a specific point in time.
Contributing safety factors
 Widespread rainfall in the days preceding 4 March 2012 resulted in saturation of the catchment
adjacent to Roto. The intensity of rainfall in the vicinity of Roto in the 6 hour period preceding
the derailment of 7SP3 led to localised flash flooding.
 The design capacity of the culvert located adjacent the 709.187 km point was insufficient to
discharge the runoff from the rain event that occurred during the morning of 4 March 2012. The
floodwater overtopped the track, causing scouring of the track ballast and associated damage
to the track formation.
 Scouring of the ballast and formation adjacent to the 709.187 km point by floodwater meant
that the track could not support the weight of train 7SP3 as it passed over the affected areas.
The resulting deformation in alignment of the track initiated the derailment.
Other safety factors
 The ARTC’s systems and operational procedures provided limited additional
information or guidance to assist network control staff in identifying and assessing a
potential threat to the serviceability of the infrastructure resulting from significant
weather events. [Safety issue]
Other key findings
 There was no anomaly identified in the train speed, handling, rollingstock condition, or
operational performance preceding the derailment.
 In the lead up to the derailment of train 7SP3 there had been adequate warning of the
significant weather event, the subsequent heavy rainfall and potential flood risk.
 The initial response by the ARTC to the significant weather event was generally in accordance
with the organisation’s policies and procedures.
 The flood event on the morning of 4 March 2012 exceeded a 50 year return rainfall event.
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ATSB – RO-2012-002
Safety issues and actions
The safety issues identified during this investigation are listed in the Findings and Safety issues
and actions sections of this report. The Australian Transport Safety Bureau (ATSB) expects that
all safety issues identified by the investigation should be addressed by the relevant
organisation(s). In addressing those issues, the ATSB prefers to encourage relevant
organisation(s) to proactively initiate safety action, rather than to issue formal safety
recommendations or safety advisory notices.
Depending on the level of risk of the safety issue, the extent of corrective action taken by the
relevant organisation, or the desirability of directing a broad safety message to the rail industry,
the ATSB may issue safety recommendations or safety advisory notices as part of the final report.
All of the responsible organisations for the safety issues identified during this investigation were
given a draft report and invited to provide submissions. As part of that process, each organisation
was asked to communicate what safety actions, if any, they had carried out or were planning to
carry out in relation to each safety issue relevant to their organisation.
Response to significant weather events
Number:
RO-2012-002-SI-01
Issue owner:
Australian Rail Track Corporation Limited
Operation type:
Rail Transport Operator – rail infrastructure manager
Who it affects:
All rail infrastructure managers
Safety issue description:
The ARTC’s systems and operational procedures provided limited additional information or
guidance to assist network control staff in identifying and assessing a potential threat to the
serviceability of the infrastructure resulting from significant weather events.
Proactive safety action taken by: Australian Rail Track Corporation Limited
A review of applied processes, sourcing of more timely information and trialling of remote
monitoring stations at selected sites has been undertaken. The ARTC has engaged the services
of a third party (March 2013) to provide an early warning network advising ARTC representatives,
including the Train Transit Manager, of the likelihood of severe weather events such as high
rainfall, winds and fire. The ARTC has also commenced trials of high water level monitoring
equipment at two locations in South Australia with the option of further rollout if proved successful.
However, having safely managed equally significant flood events at other locations on the ARTC
network by application of the existing processes, enhancement of applicable processes will be
evaluated on a cost / benefit / risk exposure basis.
Action number:
RO-2012-002-NSA-02
ATSB comment:
The ATSB is satisfied that the action taken by the ARTC has identified the risk posed by
significant weather events and that the ARTC has emphasised the need to enhance
applicable processes based on the assessment of risk exposure. The ATSB notes that the
ARTC has not identified any actions to develop/improve operational procedures for
implementation by network control staff when assessing response to a significant weather
event.
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ATSB – RO-2012-002
ATSB safety recommendation to: Australian Rail Track Corporation Limited
Action number:
RO-2012-002-SR-03
Action status:
Released
The Australian Transport Safety Bureau recommends that the Australian Rail Track Corporation
undertake further work on their systems and operational procedures that currently provide limited
additional information or guidance to assist network control staff in identifying and assessing a
potential threat to the serviceability of the infrastructure resulting from significant weather events.
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General details
Occurrence details
Date and time:
4 March 2012 – 0715 EDT
Occurrence category:
Accident
Primary occurrence type:
Derailment
Location:
Roto, New South Wales (approximately 707 track km west of Sydney)
Longitude: 33° 3.198' S
Latitude: 145° 26.607' E
Train details
Train operator:
Pacific National Pty Ltd
Registration:
7SP3
Type of operation:
Intermodal
Persons on board:
Crew – 2
Passengers – 0
Injuries:
Crew – 0
Passengers – 0
Damage:
Minor
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ATSB – RO-2012-002
Sources and submissions
Sources of information
The sources of information during the investigation included the:
 Australian Rail Track Corporation Pty Ltd
 Bureau of Meteorology
 Pacific National Pty Ltd
 Transfield Services (Australia) Pty Ltd
References
ARTC Engineering (Track and Civil) Code of Practice, Section 10 Flooding, Version 2.2 dated
08 November 2011
ARTC Glossary, Issue 2.0 – Rev. 0, dated 19 Dec 2010
Bureau of Meteorology Monthly Weather Review New South Wales March 2012 Product code
IDCKGC25R1. Prepared on 21 May 2012, ISSN 1836-3067
RISSB National Guideline Glossary of Rail Terminology, 3 December 2010
Submissions
Under Part 4, Division 2 (Investigation Reports), Section 26 of the Transport Safety Investigation
Act 2003, the ATSB may provide a draft report, on a confidential basis, to any person whom the
ATSB considers appropriate. Section 26 (1) (a) of the Act allows a person receiving a draft report
to make submissions to the ATSB about the draft report.
A draft of this report was provided to:
 Australian Rail Track Corporation Pty Ltd
 Pacific National Pty Ltd
 Transfield Services (Australia) Pty Ltd
 Office of the National Rail Safety Regulator
 Witnesses and individuals
Submissions were received from:
 Australian Rail Track Corporation Pty Ltd
 Pacific National Pty Ltd
 Transfield Services (Australia) Pty Ltd
 Office of the National Rail Safety Regulator
 Witnesses and individuals
The submissions were reviewed and where considered appropriate, the text of the report was
amended accordingly.
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ATSB – RO-2012-002
Appendices
Appendix A – Weather event and rainfall
The BoM Monthly Weather Review17 recorded that NSW received a state-wide average rainfall of
more than double the historical average for March 2012. This rainfall was from a slow-moving lowpressure trough that extended between northwest and southeast Australia (Figure 9). Humid air
from the tropics had fed into this trough generating a sustained rainband through the western and
southern part of NSW between 27 February and 4 March 2012.
Figure 9: Mean sea level pressure analysis 4 March 2012
Source: Bureau of Meteorology ©
Most of western and southern NSW recorded monthly totals three times their historical average
with locations such as Ivanhoe, about 110 km to the west of Roto, receiving more than seven
times the historical monthly average. Most of the significant rainfall recordings associated with this
very severe rain event occurred during the first week of March. The rainfalls lead to widespread
major flooding across NSW, particularly in the Lachlan and Murrumbidgee river systems
respectively to the South and West of Roto.
Rainfall data obtained from the BoM weather stations to the northwest and south of Roto (Figure
10) indicate significant rain fell in the week preceding the derailment. Heavy falls were recorded at
each station during the 24-hour period to 0900 on 4 March 2012 (Figure 11).
The BoM site at Hillston (Mount View) situated about 20 km southwest of Roto, recorded a rainfall
of 114 mm. This rainfall recording when compared to the rainfall intensity graph (mm per hour) for
the Hillston area indicates that the intensity (averaged over the 24-hour period) was equivalent to
17
Bureau of Meteorology Monthly Weather Review New South Wales March 2012 Product code IDCKGC25R1. Prepared
on 21 May 2012, ISSN 1836-3067.
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ATSB – RO-2012-002
a 50-year event (Figure 12). If the duration of the rainfall occurred during a shorter period, the
intensity would exceed a 50-year event.
Figure 10: Bureau of Meteorology weather stations adjacent Roto
Source: Bureau of Meteorology ©
Records of rainfall obtained from a resident in the Roto area showed rainfall patterns similar to
those recorded at the BoM sites during the week preceding the derailment. On the morning of
4 March 2012, the resident noted that intensity of the rainfall had been particularly heavy and the
recorded fall of 71 mm had occurred within a short period of 3 to 4 hours (would exceed a 50 and
potentially a 100-year rainfall intensity event based on the graph illustrated in Figure 12). This
rainfall resulted in fencing being washed away at several locations and scouring in the floodaffected areas of the property that had not occurred with the previous falls that week.
Figure 11: Rainfall gauging recorded between 27 February and 5 March 201218
Source: ATSB
18
Rainfall gauging obtained from Bureau of Meteorology excepting Warranary Hill (Roto), which was obtained from
gauging recorded by local resident.
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ATSB – RO-2012-002
Figure 12: Bureau of Meteorology weather station Hillston, Mount View
Source: Bureau of Meteorology ©
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ATSB – RO-2012-002
Australian Transport Safety Bureau
The Australian Transport Safety Bureau (ATSB) is an independent Commonwealth Government
statutory agency. The ATSB is governed by a Commission and is entirely separate from transport
regulators, policy makers and service providers. The ATSB’s function is to improve safety and
public confidence in the aviation, marine and rail modes of transport through excellence in:
independent investigation of transport accidents and other safety occurrences; safety data
recording, analysis and research; fostering safety awareness, knowledge and action.
The ATSB is responsible for investigating accidents and other transport safety matters involving
civil aviation, marine and rail operations in Australia that fall within Commonwealth jurisdiction, as
well as participating in overseas investigations involving Australian registered aircraft and ships. A
primary concern is the safety of commercial transport, with particular regard to fare-paying
passenger operations.
The ATSB performs its functions in accordance with the provisions of the Transport Safety
Investigation Act 2003 and Regulations and, where applicable, relevant international agreements.
Purpose of safety investigations
The object of a safety investigation is to identify and reduce safety-related risk. ATSB
investigations determine and communicate the factors related to the transport safety matter being
investigated.
It is not a function of the ATSB to apportion blame or determine liability. At the same time, an
investigation report must include factual material of sufficient weight to support the analysis and
findings. At all times the ATSB endeavours to balance the use of material that could imply adverse
comment with the need to properly explain what happened, and why, in a fair and unbiased
manner.
Developing safety action
Central to the ATSB’s investigation of transport safety matters is the early identification of safety
issues in the transport environment. The ATSB prefers to encourage the relevant organisation(s)
to initiate proactive safety action that addresses safety issues. Nevertheless, the ATSB may use
its power to make a formal safety recommendation either during or at the end of an investigation,
depending on the level of risk associated with a safety issue and the extent of corrective action
undertaken by the relevant organisation.
When safety recommendations are issued, they focus on clearly describing the safety issue of
concern, rather than providing instructions or opinions on a preferred method of corrective action.
As with equivalent overseas organisations, the ATSB has no power to enforce the implementation
of its recommendations. It is a matter for the body to which an ATSB recommendation is directed
to assess the costs and benefits of any particular means of addressing a safety issue.
When the ATSB issues a safety recommendation to a person, organisation or agency, they must
provide a written response within 90 days. That response must indicate whether they accept the
recommendation, any reasons for not accepting part or all of the recommendation, and details of
any proposed safety action to give effect to the recommendation.
The ATSB can also issue safety advisory notices suggesting that an organisation or an industry
sector consider a safety issue and take action where it believes it appropriate. There is no
requirement for a formal response to an advisory notice, although the ATSB will publish any
response it receives.
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